I think that arguing that it is not a rational being is side stepping the question, the proper question is 'granting the hypothetical that HAL is an actual, living, sentient being, what morals obligations, if any, do we have towards him?' Whether or not that hypothetical is beside the point, granting simply for the sake of discussion that it is IS possible and HAS already been done, what next?

It does raise some compelling speculations when applied to ideas like extra-terrestrials which we wouldn't know how to classify initially, and which might display a sentience which is not exactly equal to ours but still might be indicative of a being that is greater than an animal, or perhaps even somewhere between men and angels, that's why I asked my question to explore the concept of how to sort out: a.) can we determine if there is a rational soul here? (which might require divine revelation - ours or theirs), and b.) how do we treat them until we know?

However, I do think that determining that it is not a rational being was essential to resolving the OP, am I missing something? Aren't rational beings the only category that is to be treated differently from other beings (i.e. as persons, never objects)?

Sentience and intelligence do not differ by degrees, but by kind. Either an ET is nothing but a higher animal, like a dog or dolphin, or it is a rational being. And if rational, it has an immortal soul.

All living things have souls. By definition. Intelligence demands that the soul have a principle of subsisting even apart from the body which it is the form of.

How to know whether something is a highly developed animal, or a human? Language, universals. Oh animals can have some communication, but not language properly understood.

Sentience and intelligence do not differ by degrees, but by kind. Either an ET is nothing but a higher animal, like a dog or dolphin, or it is a rational being. And if rational, it has an immortal soul.

I agree. Measuring intelligence by degrees (IQ tests, etc.) is part of why there is lack of clarity in some of these matters, but since AI or a non-rational (animal) beings could demonstrate either higher or lower intelligence in any (or every) quantifiable way it could be hard to determine the rational bit. Unfortunately, it's unlikely that most of our governments would concur, since the prevailing minds don't typically recognize man's difference by kind.

Malleus Haereticorum wrote:

All living things have souls. By definition. Intelligence demands that the soul have a principle of subsisting even apart from the body which it is the form of.

By "living" you mean organic as opposed to inorganic?

Malleus Haereticorum wrote:

How to know whether something is a highly developed animal, or a human? Language, universals. Oh animals can have some communication, but not language properly understood.

True, language would be a dead give away, but until the semiotics are understood and/ or translated a language could seem as simple as zoosemiotics, particularly if, say, certain vocal ranges are beyond audible (or perhaps even currently recordable) ranges, or other means that are hard for us to sense (naturally or artificially) are used. It seems it would be easy to jump to incorrect conclusions - for instance, we might first meet an AI sent here, or we might mistake a ship for an AI when it might be organic (like on Farscape). It might well be easier to tell than my language indicates (perhaps even in terms of being probable - given what we've observed so far), but it's entertaining to consider and sometimes helps focus on the core distinctives of the reality we know.

A living thing is able to take in nutrition and duplicate itself. That definition has obvious fuzziness--are viruses alive? How about von Neumann machines? I would resolve some of that by saying that a living thing is a real unity versus an assemblage of parts, making the virus alive and the von Neumann machine not alive.